AUM OTA: check the update with full disk

Test if update doesn't break anything if there is not enough free space
on system disk.

Signed-off-by: Denis Pynkin <denis.pynkin@collabora.com>

test-cases/apertis-update-manager-ota-diskfull.yaml

+metadata:
+  name: apertis-update-manager-ota-diskfull
+  format: "Apertis Test Definition 1.0"
+  image-types:
+    minimal: [ armhf ]
+  image-deployment:
+    - OSTree
+  type: functional
+  exec-type: manual
+  priority: medium
+  maintainer: "Apertis Project"
+  description: "Ensure that failures due to disk full errors during network updates have no effect on the system"
+
+  resources:
+    - "The DUT u-boot environment must be clean: in u-boot, run: `env default -a` followed by `saveenv`"
+    - "A PC must be connected to DUT serial port"
+    - "The DUT must be connected to network"
+
+  expected:
+    - "The update wasn't applied"
+    - "System boots using the initial deployment"
+
+run:
+  steps:
+    - "Check the initial deployment"
+    - $ sudo ostree admin status
+    - "Prepare the copy of commit and deploy to allow the upgrade to the same version"
+    - "Command below shows you an initial commit ID, for instance"
+    - $ export BOOTID=$(sudo ostree admin status | sed -n -e 's/^\* apertis \([0-9a-f]*\)\.[0-9]$/\1/p'); echo $BOOTID
+    - "Get the Collection ID and ref"
+    - $ export CID=$(sudo ostree refs -c | head -n 1 | tr -d '(),' | cut -f 1 -d ' '); echo COLLECTION_ID=$CID
+    - $ export REF=$(sudo ostree refs -c | head -n 1 | tr -d '(),' | cut -f 2 -d ' '); echo REF=$REF
+    - "Create the list of files to skip and enshure there are some files in these directories"
+    - $ ls -1d /usr/share/locale /usr/share/man /usr/share/zoneinfo > /tmp/skip
+    - $ du -sh /usr/share/locale /usr/share/man /usr/share/zoneinfo
+    - "Create the commit with changed timestamp and skipped list from above to allow upgrade with recent update file"
+    - |
+        $ export NEWID=$(sudo ostree commit --orphan --tree=ref=$BOOTID --add-metadata-string=ostree.collection-binding=$CID --bind-ref=$REF --timestamp="1 year ago" --skip-list=/tmp/skip); echo "New commit: $NEWID"
+    - "Deploy the prepared commit"
+    - $ sudo ostree admin upgrade --allow-downgrade --deploy-only --override-commit=$NEWID --reboot
+    - "Wait until the system is booted again and check the deployment"
+    - $ sudo ostree admin status
+    - "The booted commit (started with '*') must have ID which we prepare and the initial commit ID should be marked as '(rollback)'"
+    - "Check booted deployment have no file objects which we skip"
+    - $ du -sh /usr/share/locale /usr/share/man /usr/share/zoneinfo
+    - "Remove the initial deployment"
+    - $ sudo ostree admin undeploy 1
+    - "Reboot the system"
+    - "Check the current deployment"
+    - $ sudo ostree admin status
+    - "Need to monitor the journal log"
+    - $ sudo journalctl -ef --unit apertis-update-manager &
+    - "Check the free space on rootfs, calculate the size of file to leave insufficient free space for upgrade to happen
+      (this prevents the unexpected reboot during the test caused by other services).
+      For instance, in the case below, NUM value would be 1451. It is the result of the calculation 1823-348-24,
+      there 24 is a magic constant, so that almost, but not all free space is used.
+      The free space can be calculated with command line `sudo df -B 1M / | grep / | awk '{print $2-$3-24}'`"
+    - $ sudo df -B 1M /
+    - | 
+        >Filesystem           1M-blocks      Used Available Use% Mounted on
+        /dev/mmcblk0p2            1823       348      1365  21% /
+    - $ sudo dd if=/dev/zero of=/var/bigfile bs=1M count=<NUM> ; echo "dd completed!"
+    - Wait until 'dd' completes (it should take time),  you will see the output similar to
+    - |
+        >1521483776 bytes (1.5 GB) copied, 82.1661 s, 18.5 MB/s
+        dd completed!
+    - "Enable network updates with CLI tool"
+    - $ sudo updatectl --check-network-updates
+    - "The update should fail with error message"
+    - |
+        >** Message: 20:59:57.249: Network connected: Yes
+        ** Message: 20:59:57.251: Auto update status: active
+        ** Message: 20:59:57.251: Ostree upgrade poll starting
+        ** Message: 20:59:58.697: Ostree upgrade failed: min-free-space-percent '3%' would be exceeded
+    - "Set reserved space for ostree to '0'"
+    - $ sudo ostree config set core.min-free-space-percent "0"
+    - "Restart the Apertis Update Manager"
+    - $ sudo systemctl restart apertis-update-manager
+    - "Enable network updates with CLI tool"
+    - $ sudo updatectl --check-network-updates
+    - "The update should fail with some error message related to disk space, for instance:"
+    - |
+        >** Message: 21:02:31.972: Network connected: Yes
+        ** Message: 21:02:31.974: Auto update status: active
+        ** Message: 21:02:31.974: Ostree upgrade poll starting
+        ** Message: 21:02:33.800: Ostree upgrade progress: 2 metadata, 0 content objects fetched; 284 B transferred in 1 seconds
+        ** (process:532): WARNING **: 21:02:33.801: Cannot check the ID in black list: No such file or directory
+        ** Message: 21:02:41.054: Ostree upgrade failed: Error writing to file descriptor: No space left on device
+    - "Remove temporary file"
+    - $ sudo rm -f /var/bigfile
+    - "Reboot the system"
+    - $ sudo reboot
+    - "Check that there is only one deployment"
+    - $ sudo ostree admin status